Tread clamping device for weaving machines



United States Patent Inventor Johann Sting],

' l0 Bottgerstrasse, Hohenberg/an der Eger,

Germany App1.N0. 765,440 Filed Oct. 7, 1968 Patented Oct. 13, 1970 Aignee George Fischer Ltd. Brugg,

Brugg, Switzerland Priority Oct. 6, 1967 Switzerland 14033/67 TREADCLAMPING DEVICE FOR WEAVING v 50 Field ofSearch 242/147149:139/116,122l27P References'Cited Primary Examiner-Henry S. .IaudonAlt0rney-Rodney C. Southworth ABSTRACT: The present invention relates toa thread clamping device for weft thread or threads for use in a weavingmachine with weft thread supply cones located outside the shed whichweft threads are inserted into the shed of a fabric being woven bycarriers or other means for the purpose.

MACHINES 8 Claims, 7 Drawing Figs.

U.S.Cl 139/122, 139/127 Int. Cl D03d 47/18 1:1" mm '7 8 I" 17 5; J 18Patented Oct. 13, 1970 3,533,451

Sheet 1 of 3 INVE TOR. Johann Shngl BY ha a? Patented Oct. 13, 1970Sheet 2 of 5 INVEIQTOR. Johann Sfingl Patented Oct. 13, 1970 3,533,451

Sheet 3 of 3 'INVENTOR.

Johann Sh'ngl 1 TREAD CLAMPING DEVICE FOR WEAVING MACHINES BACKGROUND OFTHE INVENTION In a weft insertion principle according to which the weftthread last inserted in the fabric extends temporarily via a threadcontrol member and a primary brake mechanism, to the weft supply cone,that weft is supplied to a right-hand weft insertion member by means ofa depresser or pull-down member, the said insertion member then passingthe weft to the center of the fabric as a loop where it transfers it asa measured pick to a left-hand insertion member. The weft is then cut atthe selvage where reversed. This principle requires, after transfer ofthe thread, actuation of a device which clamps the thread coming fromthe supply cone so that no thread can be obtained thence and that thecut weft end can be extended by the left-hand insertion member.

In color or other work in which a plurality of feeders with accordinglynumerous threads and supply points, there arises the problem of locatinga like number of thread clamping devices on the machine frame so as tosave the maximum of space, or to arrange it in the space available. Withknown devices clamps for an eight-color loom, for example, take aninordinate space. It is an object of the present invention to provide athread clamping device which is simple in construction and operation anddoes not require high precision manufacture to provide a maximum ofoperational reliability and which also occupies a minimum of space.

SUMMARY OF THE INVENTION The thread clamping means according to thisinvention is characterized in that for each thread it comprises two leafsprings that face each other and are movable to and from an openposition into a clamping position and which have overlapping portions ofconsiderable area. Weft thread guides restrain the wefts to run throughthe clamps only at the overlapping areas. These leaf springs are fixedin support means, one of which is movable relatively to the other sothat the overlapping portions engage in the clamping position so as toprovide a clamping action and lock the thread against movement, but whenopened, free it to impose no drag on it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagrammatic view of theweft insertion principle, also showing the clamp as shown in plan;

FIG. 2 is a sectional view of an open thread clamping device accordingto this invention;

FIG. 3 is a similar view of the clamping device according to thisinvention in closed position;

FIG. 4 is an elevation of a thread clamping device according to thisinvention designed for eight weft threads in different colors;

FIG. 5 is a section of the thread clamping device according to FIG. 4and taken at line A-A;

FIG. 6 is a view of a thread clamping device according to a modificationof the invention with adjustable clamping leaves for four weft threads;and

FIG. 7 is a section of the thread clamping device according to FIG. 6,taken at line 8-3.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a diagrammatic view ofa principle of weft insertion to which the invention may well beapplied. The fabric .1 havinga right-hand selvage 2 which may preferablybe a false selvage, is being woven in a loom with a slay 3, slay support4 and a reed 5. Indicated generally is a driving unit 6 with a guide 7for the weft insertion member 8. Located between the slay 3 and theguide 7 is a thread pull-down member 9 which supplies the weft thread toa carrier 11 fixed at the end of a weft insertion rapier or member 8 andfeeders 12 which selectively supply the weft thread coming from thecones 13 to cone covers 14 is the thread clamping device 16. Thecohstruction and operation of the basic loom parts here are shown in US.Pat. No. 2,641,285. From a weft thread 17 last iiiserted, the thread 10passes via a loop 18 to the carrier lI,

that feeder 12 which is in feeding position, and finally, extends backto the supply cone 13. After the weft 10 has been trari'sfered by theright-hand insertion member 8 to the left-hand ihsertion member 19, thesaid thread is cut by a thread cutting attachment 20 at the loop 18 andpreferably between the maih body of the warp and the warp at the falseselvage 2. This lefthand carrier 19 extends the cut end to complete thepick in a known manner. Driving means (not shown) force mobile clampingsprings 21 against stationary clamping springs 22 of the thread clampingdevice 16 at this time, the weft thread ll) located between being heldfast so no weft is drawn from the cone after enough for a pick has beenmeasured.

FIG. 2 is a view of an open thread clamping device whibh basicallycomprises a stationary clamping spring 22 and a mobile clamping spring21 and which does not necessarily requll'e parallel relationship betweenthe clamping springs 21, 22 owing to its manner ofoperation.

FIG. 3 is a view of a closed thread clamping device in which, thanks tothe resiliency of the clamping springs 21, 22 an accurate fit of theoverlapping portion 23 is possible even after the rest positionaccording to FIG. 3 is reached. This clampitig principle enables weftthreads of different counts to be clamped without any particularadjustments or preparations:

bracket being, in effect, an integral part of the plate. Attached to thebase plate 24 by means of screws 27 is a segment or rlin 28 in which theclamping springs 22 are inserted, preferably by being soldered intoslots in the rim. The hub supports a shaft 30 fixed by a set screw 29 onwhich a mobile segment hub 32 is oscillatable on needle bearings 31. Itis secured against axial displacement by means of washer 33 and screw34.

Further clamping springs 22 arerecessed in projections or sectors fixedto and projecting from hub 32. Mounted on a tenon 36 rigidly connectedto the projection or sector is a ball or other bearing 37 whichlaterally abuts against a spacer 38 and a washer 41 attached by means ofa screw having a grooved head. Guided in a bracket or holding portion 26by guides 42 is a positioning member or plunger 43 which is moved bycontrol units e.g. cam means (not shown) and acts. against the action ofa tension spring 45 hooked into the groove 39 and about a bolt 44, onthe ball bearing 37. The segment moved by this plunger and spring in thedirections indicated by arrow 46 and the clamping springs 21, 22 aredisplaced against or away from one another. Motion is limited to only afew degrees of oscillation.

' A flat annular, segmental bar 47 is attached to the base plate 24 bymeans of screws 48, one at either end, and is provided with a number ofeyelets 49 identical with the number of pairs of clamping springs, theweft thread 10 being passed through them between the clamping springs21, 22 and then drawn away through eyelets 50 in the base plate'24.

FIG. 6 is a viewof a modification of the invention with a threadclamping device with adjustable clamping springs for four weft threads,and FIG. 7 is a section of the same clamping means, the same clampingspring principle being applied, in this embodiment as well except thatmotion is rectilinear. A slide guide 51 is provided with thread guideeyelets and bores 53, the later rotatably supporting bolts or pins 55held axially by means of securing rings 54. Attached to the bolts areholders 56 with soldered-in clamping springs 57 and fixing pins 58.

The slide guide 51 is provided with adjusting screws 59 which actupon aright-hand and left-hand leg 60 of the holder 56 so that the clampingsprings can be individually swivelled.

Normally these leaf springs are adjusted to position close to therunning weft and then retained in that set position. The slide guide 51holds the slide 61 actuated in the direction of arrow 62 by drivingmeans (not shown), e.g. by cams. It is provided with soldered-inclamping springs 63 and secured by plates 64. Slide 61 has an easyrectilinear motion in its slide channel and is moved to bring springs 68into pressure engagement with springs 57 with the weft between when thatweft is to be locked against withdrawal. A member 66 equipped witheyelets 65 is firmly bolted to the slide guide 51. The thread 67 passesthrough the eyelets 52, 65 andbetween the clamping springs 57, 63, andit may pass a variety of different counts in the embodiment of theclamping unit 68. In other words, the count, type or character of theweft makes little difference.

While examples of four and eight color units are given, the device maybe adapted to a single weft or to any reasonable plurality. It is to benoted that for multiweft work one simple motion opens all clamps andcloses all. With the system herein involved wefts not being drawn arereleased along with the one that is, however, this only permits theinactive wefts to be extended slightly as the fabric to the selvage ofwhich they are connected moves away. Actually, only the running weft isaffected in normal patterns. Only the feeders 12 for two wefts are shownhere, but there an equal number of these for the number of wefts inaction. Pattern control governs the presentation of weft as desired.

This disclosure of a preferred embodiment of the invention is to beinterpreted as illustrative of forms the invention may take andmodifications will readily occur to those skilled in the art. Theinvention is not to be restricted except by the scope of the appendedclaims wherein the novel features desired to be protected by LettersPatent are set forth:

I claim:

1. A thread clamping device for weaving machines of the type in whichweft is drawn from a supply positioned outside a shed of a fabric beingwoven and is inserted as a pick of weft by means moved into and from theshed, characterized in that, the clamping device includes two relativelymovable support means, cooperating leaf springs having overlapping endsfunctioning as a pair, one of which is fixed in each of said supportmeans, guide means for the weft positioned to guide it between theoverlapping portions of said leaf springs, and means to move saidsupport means to separate said leaf springs and to press them togetheras the weft is to be released or locked against withdrawal from thesupply.

2. A thread clamping device as claimed in claim 1, wherein a pluralityof pairs of leaf springs are fixed in said support means and a likenumber of guide means for the weft are provided.

3. A thread clamping device as claimed in claim 2, wherein the guidemeans are mounted in the support means.

4. A thread clamping device as claimed in claim 2, wherein the supportmeans comprise sector-shaped members, hubs from which said membersextend, one of said hubs and its sector-shaped member being fixed andthe other of which is movable.

5. Mechanism as defined in claim 2, wherein the movable support means ismoved in a relatively small angular oscillation to open and to close thesaid leaf springs.

6. Mechanism as defined in claim 2, wherein means for moving saidmovable support means includes a plunger pressing against a part of thesupport means and a spring for returning the parts to the oppositeposition.

7. Mechanism as defined in claim 2, wherein leaf springs in one saidsupport are fixed therein, and means for adjusting the leaf springs inthe other support which includes swivelable holders, one for eachspring, and threaded means to adjust and retain said holders in a fixedposition to which they have been adjusted.

8. Mechanism as defined in claim 2, wherein said support means areguided and moved in a rectilinear pathway.

